In the recent version (see
dev branch of my mod) I refactored and rewrote it from scratch. I also got permission (see README of my mod) from the author of the other mod to use his code.
In this situation, do I have a freedom over choosing which license I can choose, in this case WTFPL, or must I stick only to GPL compatible licenses?
I'm still going to give credit to the original author of the mod, but I'm unsure about my licensing situation and control over my code.
Thank you for attention!